Art of fusing ores.



RAOUL PIERRE PICTE PATENT OFFICE.;

T, or rams, FRANCE.

ART 02E FUSING CRES.

1,230,431. speciaeauon of Letters Patent. Patented June V19, 191 '7.

Application filed October 29, 1913, Serial No. 798,056. Renewed May 12, 1917. Serial No. 168,316.

To all w kom' it m ay concern Be itknown that I, RAoUL PIERRE PIo'rET, of 21 Rue de la Rochefoucauld, Paris, France, engineer, have invented a new and useful Art of Fusing Ores, which improve* ment is fully set forth in the following specification.

' transforms `the carbonio acid into carbonio oxid 'thus allowing the layer of mineral above it to be reduced and so on.

The excess 'of-carbon brought to very high temperatures'at the bottom of the furnace causes the fusion of the gangue 4which becomes slag and of the iron which passes out as cast or carburized iron.

ThisA invention has for its object-a new process which allows 'uncarburized soft iron and a completelyflui'd slag to be obtained at the bottom of thefurnace even from the most refractory minerals.

The theory of the new process is the following First a very exact analysis of the constitution ofthe ore is made to ascertain what oxid 'of iron is to be reduced and the weight of carbon necessary for this operation..

By analysis of the gangues ,it is known to what temperature they must be brought for complete fusion.

When these two points are known a blast, furnace is built which is very similar to the usual type but diers in'one essential .particular. The lower base of the furnace is formed of two superposed sections one of which is supplied with a special current of carbonio oxid led in through nozzles by blowers.

The upper `nozzles are supplied with the ordinary air blast while the lower nozzles are supplied partly with a. current of carboni' oxd and partly with acurrent of air ess commercial oxygen. Y

The blast nozzles of the lower section cause by their proximity an intimate mixture between the carbonio oxid and the commercial oxygen. s

The content in oxygen with respect to the nitrogen and the ratio 4of the volume of oxygen blown. into the volume of the cal"- bonic oxid should be known with exactitude' and be regulable, this being an essential condition. v

It may be supposed for example for the sake of clearness that the ores present represent 29% of oxygen with respect to the weight of pure iron contained in the gangue.

` i It is known that foi a content of soft iron a certain and exactl,4 calculable weight of carbon 1s required to transform the oxygen linked to the iron of the oxids to -be treated into carbonio oxid.

By studying the gangues it will be found for example that it is necessary to bring them to a temperature of 17500 C. in orderl these gangues because the gases of combusslightly greater than the v`fusing point off tion should furnish the latent heat of ful sion at this raised temperature.

lV hen these two points are fundamentally known for a given quality of ore, a gasometer is filled with the mixture of oxygen and nitrogen whichwill furnish for the com bustionl of a given volume of carbo/nic oxid, a temperature in accordance/ ith the Yanalyscsnnd the fusing pointsfan a blow# ing compressor is fed with saidf-,colnmercial oxygen, Carbonio oxid mixed. or Vnot with i nitrogen is stored in a second asombter.

The carbonicloxidmay be'f'directly collected from the blast 'furnace any desired maffner. V

AThe relative proportions of the carbonio oxid and the commercial OXYgD which should be blown into thebase ofitlefurnace to attain the temperature on th ',one hand anaknown, and also with normal .orkingof the blast furnace the quantity ofheat needs,- sary' on the other hand completly"it()A the ironv and the slag. i

or made in The two blasts are regulated with exati'- iss i- 4equidistant in the thickness tude, one acting by the compression of the commercial oxygen into doses of oxygen, the other furnishing the necessary volume of carbonio oxid and owing to such combustion the iron will only fuse in contact with the carbonio oxid and the oxygen and will not be'contaminated with any carbon because this will have completely disappeared in the reducing layers of the blast furnace.

But fusion under these conditions will'not to any degree furnish cast iron. The iron will be soft and will remain so during fuslon.

If on the contrary it is desired to leave a certain quantity of carbon in the iron it is necessary to add this quantity to the. carbon placed in the parallel layers introduced into the blast furnace with the layers of ores and such additional carbon will be found with exactitude in the melted metal.

The ten'i'perature of the llame produced by the carbonio oxid and the oxygen will bo regulated `only by the necessity of the: complete fusion of the ore for without this there will be danger of obstructions.

The gases which rise to the top of the. forl nace above the section Where fusion oi the ore takes place are added to the. atnlof-sphericv air which has for its object the reduction ol' 'the carbonio oxid contained in the superposed layers.

All the oxygen and the carbonio oxid only increase the Volume ofthe reducing gases.

en the ores contain silicon and titanium the temperature of fusion may attain 1800 C.' n

The gases which pass out of this zone opcrate under these conditions at a higher temperature than in the case of ordinary less refractory ores, the 'reduction of the oxids at this high temperature is much more rapid.

The drawing illustrates diagrammatically in section a blast furnace for carrying out this invention. y

a are the Walls formed of highly refractoryf bricks.

he superposed layers of ore and carbon areintroduced through the mouth of the furnace.,

represents the ore and c the layers of on.

As the layers descend of themselves the thickness ofthe layersbecomes less.

vIn'the drawings these layers are shown der to showby the shading f the 'layers c of carbon at.

the tol); 6" shows the thickness ot' tbe central layers and c" the last layer o'l| carbon above that portion ol' the l'urnace where fusion takes place. 'l`he tu'yers rl f/ lead in atmospln-ric air which has passed through ordinarv heaters to raise 'its temperature before the entr ol' the gases into the reducing zone, the t\v vers lead in carbonio oxid and air containing more or less tannn'iereial oxygen.

c is .the fusion zone ol' the iron and lslag.

The chamber j is tberel'ore brought by a combined systematic. combustion to the criti cal temperature ot' the 'fusing point ol' 'the ore and tbe immediate separation oi" the fused sott iron from the slag. These. two 'used liquids l'all into the poclv'et where the)y pass out through the orifices /l and l', the .slag at /l and the iron at 1'..

The pocket r/ may of course operate as a Bessemer converter.

Oxygenizcd air nralv be blown in at tbc. bottom ol' the pocket ilit be desired to eonlplete the purilication ol' the metal. lli therel'ore' it is desired to resume the normal Working ol' the blast 'urnace :wording to` theA rules ol' the new process one proceeds as follows: i

t the bottoni oil' the blast l'urllnce there flows outconstant .or intermittentl a pure. metal trausfrn-med according to tbe nature of the. materials directly introduced l'or this purpose into steel ol' the duality desired or as sol't iron without: carbon or impurity. 'lhe metal Vpasses out at l' and represents the normal output of the blastI furnace.. The molten slag separates from the metal, floats at the surface and passes away at L.

Above, these i'used masses gaseous currents are led in consisting ol' carbonicv oxid. oxygen :unl nitrogen retained in the mixture as a temln'rature regulator.

ll' the chamber f the lusion zone c the orc fuses rapidly however refractory the elcments l'orming the gangue may be..

The. gases coming from the. ordinary blower pass through the twyers (Z and mix with theA very bot gases passing out of the.

'chamber pipes' formed in thethicknessof the Walls ofthe blast furnace or by-v any otherarrangement.

l) tl tities of carbonio acid but large'quantities of` carbonio oxid andnitrogen.

These gases are collected and the carbonio oXid compressors are fed from the pipes for the outlet of thel'gas and furnish the volume y of carbonio oxid necessary for the fusion of the ores in the chamber g.`

The excess of carbonio o'xid produced may-Av be employed for any desired purpose;

The action `of the blast furnace is there- ,ifore ,continuous and ,need only be interrupted when a change is required in the quality i of the producti- In effect the preparation of steel, the introduction of special material, the blowing of the mass, require for each tappingI a .certain time for preparation but do not affect in any way the normal and continuous treatment of the ores. /All the material 0f the blast furnace, the bases of the blowers, the inner liningl of the walls of the chambers e and f, are specially selected to resist the highest temperatures.

It ishobvious that this invention may be applied toithe treatment of other metalsthan iron. A

Claims: o

1. .The recess of smelting ores to obtain the uncar onized metal or metal having a given degree of carbonization, which consists in stacking a furnace with layers of ore of a previously ascertained composition, alternating with layers of carbon, the amount of carbon 'in said layers being calculated to be consumed to the desired extent and to completely reduce the ore before reaching the fusing zone, and introducing at the said fusing zone Aof the furnace a mixture of oxy en, nitrogen and carbonlc oxidcalculate to produce the temperature requlred to bring the gangue of t e ore to complete fusion. I

2. The rocess ofsmelting ores to obtain the uncarbon'ized metal or metal having a 'ven degree of carbonization, which consists in stacking a furnace with layers of ore of a previously ascertained composition, alternatllated to produce the tem ing/with layers of carbon, the amount of carbon in said layers being calculated to bel consumed to the desired extent and to cornpletely reduce the ore before reaching the fusing zone, introducing at the said fusing zone ofthe furnace a mixture of oxygen, nitrogen and carbonio oxid calculated to produce the temperature required to bring the gan e of the ore to complete fusion, and intro ucing air into the furnace above said zone.

3. The process of smelting ores which oonsists in stackin a furnace with layers of ore of a previous y determined composition, alternatin amount o carbon in said layers being calculated to be entirely consumed and to entirely reduce the ore before reachin fusion zone, introducing at the said lsion zone a'mixture of oxygen, nitrogen and carbonic` oxid calculated to produce the' temrperature required to bring the gangue of the ore to complete fusion. I

4. The process of smelting ores which consists'in stacking a furnace with layers of ore of a previously determined composition, alternatin with layers of carbon, the amount o carbon in said layers being calculated tofbe entirely consumed and to entirely reduce the ore before reachin the fusion zone, introducing at the said usion zone a mixture of oxygen, nitrogen and carbonic oxid calculated to produce vthe temperature required to bring the vgangue of the ore to complete fusion', and introducing air into the furnaceabove said zone.

5. The rooess of smelting ores to obtain the uncar onized metal or metal having a given ldegree of carbonization, which consists in stacking a furnace with layers of o re of a previously ascertained' composition, alternating with layers of fcarbon, the amount of carbon in said layers being cal; culated to be consumed to the desired extent and to completely reduce the `ore before- Vreaching the fusin zone, introducing at the said fusing zone o the furnace a mixture of oxygen, nitrogen and carbomc ox'id calcubring the gangue of t e ore to complete fusion, and blowing oxygenized air into the molten metal for further urifcation.

In 4testimony whereof have signedths specification in the presence of two subscribing witnesses.

RAOUL PIERREr PICTET.

Witnesses HANsoN CLCoxn,

erature required to' with layers of carbon, the.

the 

